A boxable drywall corner trim that can include an elongated semi-rigid member that forms a pair of flanges joined at a grooved hinge along a centerline. Each of the flanges can have a thinner part and a thicker part joined at a step that is approximately parallel to the centerline a predetermined distance from the centerline. The thicker part of the flanges can form a protruding nose member that makes the piece boxable by preventing the cross-over of wet drywall mastic or mud from one flange to the other. The thinner portion of the flange may optionally be perforated with a pattern of punched holes of any configuration throughout the flange assembly. The piece can have a wall-facing paper or other fibrous layer of material that has a tacky adhesive on its wall-facing side. The adhesive can be in a pattern of dots, ridges, lines or any other pattern, or the adhesive can be continuously coated on the surface. This tacky adhesive allows the piece to be applied to the corner, moved, removed and re-applied if necessary.